I submitted my manuscript to a journal from 1 month ago in scholar one. The status changed to admin check to under review after one week. Now, it shows Awaiting Decision.
Does this mean that the paper has passed the editorial check and the external reviewer completed?
It depends. If you know that in this journal (and you discipline) the papers are typically reviewed fast (e.g., one month), then it indeed likely that your paper is already after peer-review. In contrast, if in this journal the peer-review typically takes several months, then it might be long desk-rejection. It is indeed not rare to get desk rejection after several weeks. Also, keep in mind rejection rate without review in your journal. If it is low, then it more likely to be already after review.
If it has been "under review" for some time, then yes - the external reviewers are done. If you didn't see "under review", then the editor is making a decision without consulting reviewers, which is usually a bad sign.
